How to get correct results when baking a fluid simulation
There are several issues:


The scene is upside down. The Z axis (blue) always points up in world space. In the file provided, the view is upside down and the blue arrow appears to be pointing down. When righted, it looks like this:



So in your scene the the fluid emitter is actually below the domain and collision objects.
The fluid domain is always a box shape, as it uses the object's bounding box. When assigned to a non-box shape, this means that it will be a cuboid with the same dimensions as the shape.

If you replace the icosphere with a cube, the reasons for the odd behavior become clearer:


Note that I duplicated the domain object in this screenshot so that the domain bounds would be visible at the same time as the fluid
The collision planes are non-manifold. The fluid simulator has no way of determining where the insides and outsides of the 2D planes are, so it will guess, usually resulting in strange behavior.  

Related: Fluid not filling container completely


If the fluid emitter object is moved above the collision objects and the collision objects are given volume and correctly oriented normals, then it appears to work: